1. Field of the Disclosure
This disclosure relates to a backlight unit, and more particularly to a backlight unit that is easier to slim and simplify the configuration, and a liquid crystal display (LCD) device with the same.
2. Description of the Related Art
Cathode ray tubes (CRTs) correspond to one of display devices which are widely used. The CRTs are mainly used as monitors for TVs, measuring apparatuses, information terminals, and so on. However, the heavy weight and large size of the CRTs have been a major hindrance to the manufacturing of small, light electronic products.
To address this matter, LCD devices are gradually being used in a wide range of applications due to their advantages such as light weight, thin thickness, and low power consumption. Furthermore, LCD devices are being manufactured to have even larger screens, be thinner, and consume less power, in order to meet requirements of users.
LCD devices display images by controlling the amount of light transmitted through liquid crystal. However, LCD devices are not self-illuminating display devices, unlike CRTs. As such, an LCD device includes a backlight unit configured to have a separate light source, which provides light necessary to display an image, and disposed on the rear surface of an LCD panel. The backlight unit is classified as either an edge type or a direct type in accordance with the disposition of its light source.
The LCD panel is used to display an image. To this end, the LCD panel includes a thin film transistor substrate and a color filter substrate disposed to face each other and combined with each other by a seal pattern. Also, the LCD panel further includes a liquid crystal material which is injected between the thin film transistor substrate and the color filter substrate after the combination of two substrates.
The edge type backlight unit includes a light source which is disposed in a position corresponding to a side of the LCD panel. Also, the edge type backlight unit irradiates light emitted from the light source onto the entire surface of the LCD panel using a light guide plate. As such, it is easy for the edge type backlight unit to be made thinner. Therefore, the edge type backlight is mainly used for middle and small sized LCD devices.
On the other hand, the direct type backlight unit includes a plurality of light sources arranged at a fixed distance under the LCD panel. The plurality of light sources directly applies light to the rear surface of the LCD panel. The direct type backlight unit can provide a higher brightness and a wider luminescent surface than the edge type backlight unit because it employs a plurality of light sources. Accordingly, the direct type backlight unit is mainly used for large sized LCD devices.
An LCD device with the edge type backlight unit enables light output from the light source, which is disposed at a side area, to pass through the light guide plate. At this time, light from the light source is converted into two-dimensional light by the light guide plate. The LCD panel displays an image using two-dimensional light output from the light guide plate.
Such an LCD device includes an LCD module with the LCD panel disposed on the backlight unit. The LCD panel is combined with the backlight unit by engaging a top case and a bottom cover of the backlight unit, thereby completing the assembling of the LCD module. The top case is formed to encompass the upper surface edges of the LCD panel.
The assembled LCD module is placed within a cavity between upper and lower system cases which encompass the top case and the bottom cover, respectively. Also, a system driver configured to drive the LCD module is installed within the lower system case, thereby providing a completed LCD device.
In this manner, the ordinary LCD device is configured with complexity. As such, the assembling time of the ordinary LCD device becomes longer. Therefore, it is difficult to minimize the manufacturing time of the LCD device. Moreover, the complex configuration of the ordinary LCD device makes it difficult not only to reduce the total weight but also to implement slimness.